Heavy rain, mudslides possible as L.A. heads into a week of storms
Southern California could see seven straight days of rain as the region gets hit with five storms that could last through Thursday.
Authorities warned mudslides are possible, both in the storms that hit Saturday morning and the sequel — expected to arrive Sunday night and persist into Monday — which “could be the strongest storm of the season so far,” National Weather Service meteorologist Richard Thompson said.
“It’s just a train of storms,” Thompson said. He urged people living in and near the areas burned in recent wildfires to stay vigilant.
Though the storms aren’t expected to be as severe as the one that unleashed devastating mudslides in Montecito in 2017, killing 23 people and destroying 130 homes, officials warned that deadly flows of mud and debris can still happen, even in a comparatively milder storm. A burst of rain over a small geographic area could cause deaths.
“People should still be cautious. Sometimes you can get these deluges that last about an hour, but that’s all you need to shake loose those hillsides,” climatologist Bill Patzert said.
On the National Weather Service’s new five-level scale of weather impacts, officials forecast the risk of flows of mud, rocks and other debris in the recent burn areas to be “elevated,” in the middle of a scale that extends from “no impact” to “extreme” — equivalent to the storm that ended up producing the deadly mudslides in Montecito.
“I don’t think we’ll see a Montecito event at this point,” Thompson said, although the forecast could change. “Anyone who lives in or near the burned areas needs to remain alert.”
The effect from these storms could be the same or even greater than that of the storm last weekend that dumped mud from the burned landscape of the Woolsey fire onto Pacific Coast Highway, trapping three cars up to 4 feet deep.
“If you’re on PCH this week, definitely uncover your moon roof,” Patzert said. “Keep one eye up and one eye down.”
Southern California hasn’t seen a consecutive string of storms like this in years, he added.
“It’s usually less than 10 storms a year that make up our season” of rain, Patzert said. “This is like half of what you’d get in an entire season in a week.”
The back-to-back nature of the storms could be problematic as an increasing amount of water soaks into the soil. “The longer it goes, the higher the chances of the hillsides” becoming unstable, Patzert said.
The storms are coming from the north Pacific Ocean, and some will have a subtropical component, “maybe a little atmospheric river boost,” Patzert said. “And you can see, it’s been pretty chilly lately.”
Though scientists have been monitoring El Niño conditions in the tropical Pacific Ocean, the climate pattern still hasn’t clicked into place.
The first storm is expected to drop 1 to 2 inches of rain and perhaps up to 3 inches in certain areas in San Luis Obispo, Santa Barbara and western Ventura counties, while L.A. and eastern Ventura counties are expected to get half an inch to 1.25 inches.